<template>
    <div>message的值：{{ message }}</div>
    <div>obj.message的值：{{ obj.message }}</div>
</template>

<script setup>
       import { reactive, toRef } from 'vue'
       const obj = reactive ({ message:'黑发不知勤学早，白首方悔读书迟'})
       const message = toRef(obj, 'message')
       setTimeout(() => {
        message.value = '少壮不努力，老大徒伤悲'
       }, 2000)
</script>